Watermarking system that executes received watermarking instructions to embed a watermark

A method of managing keys is provided. According to one exemplary method, digital content data encrypted with a first encrypting key is decrypted using a first decrypting key, and re-encrypted using a second encrypting key. A second decrypting key is encrypted using a third encrypting key to produce an encrypted second decrypting key. In some embodiments, an encrypted first decrypting key that was encrypted using a fourth encrypting key is received, and the encrypted first decrypting key is decrypted using a fourth decrypting key to reproduce the first decrypting key. An application for use on a computer system is also provided.